The commission’s own research shows that such a tax would have a negative impact on growth: Algirdas Semeta, the European commissioner for taxation, said this week that it would cut GDP across the EU by about 0.5 per cent. At a time when Europe is struggling to grow at all – and when growth is essential to dragging its economies out of the mire – this would be a crippling reverse.

One would have thought that this assessment would be enough to kill the idea stone dead – especially since the Government has made it clear that Britain will veto the plan, since such a tax would only make sense if it were introduced globally, to avoid a mass exodus of financial institutions from the area affected. Mr Barroso, however, has other ideas....